Computer Science 455

Instructor: R. P. Burton

Sixth Quiz

April 16-17, 2007

Name _________________________________________ Score ____________/33

1. If a ray intersects a plane containing a polygon, and if the projection of the intersection is inside the projection of the polygon, then the ray intersects the polygon.

   1. true

   2. false

(a)

2. The ray-polygon intersection problem, as discussed in class, is solved

   1. by shooting rays through the vertices of the polygon and comparing their directions to the (potentially intersecting) ray’s directions

   2. by solving the ray-plane intersection problem and then doing an inside-outside test

(b)

3. For the purposes of ray-box intersection, a slab is

   1. effectively infinite in all but one dimension

   2. constrained in two of three dimensions

   3. constrained in all three dimensions

(a)

4. The ray is specified _____ and the box is specified _____.

   1. implicitly, implicitly

   2. implicitly, explicitly

   3. explicitly, parametrically

   4. parametrically, explicitly

(d)

5. The intersection of a ray with a cylinder, cone, ellipsoid, … is solved in part by solving a ______ equation.

   1. linear

   2. quadratic

   3. cubic

   4. quartic

   5. higher order

(b)

6. An appropriate inverse mapping for a circle is mostly a problem of converting from Cartesian to polar coordinates.

   1. true

   2. false

(a)

7. The inverse mapping for a cylinder _____ introduces distortion.

   1. always

   2. sometimes

   3. never

(b)

8. If two (energy distribution) spectra produce perceptibly equivalent colors, the spectra can be expected to be similar.

   1. always

   2. sometimes

(b)

9. Fractal geometry is closest in age to

   1. you

   2. the course instructor

   3. the State of Utah (statehood was granted in 1896)

   4. Joseph Smith (b. 1805)

   5. Galileo (b. 1564)

(a)

10. Except for purely mathematical purposes, the utility of fractals is limited to graphic presentations of artificial, but plausible scenes (and other intriguing, but artificial images)

    1. true

    2. false

(b)

11. What is the length of the perimeter of the Koch snowflake? Assume the initial length of a side of the equilateral triangle is 1.

    1. between 3 and 6

    2. 6

    3. 12

    4. lots more than 12

(d)

12. What is the reason for generating fractals with functions in the complex plane?

    1. fractals have an imaginary component

    2. it permits the x and y coordinates to be separated easily

    3. (fractals cannot be generated with functions in the complex plane)

(b)

13. For random midpoint displacement, which of the following is not true?

    1. every point along an edge has an equal probability of being displaced

    2. displacement inward and displacement outward are equally probable

    3. displacement generally is proportional to the length of the edge

    4. (all of the preceding are true)

(a)

14. The Koch snowflake demonstrates

    1. exact self-similarity

    2. statistical self-similarity

(a)

15. For “natural” scenes, the fractal dimension typically is ____ than the Euclidean dimension.

    1. less than 25% greater than

    2. between 25 and 50% greater than

    3. more than 50% greater than

    4. twice as large as

(a)

16. If you were to dig a hole in rocky soil (north Orem, for example), the quantity of rocks of each size would be _______ the relative size of the rock.

    1. independent of

    2. proportional to

    3. inversely proportional to

(c)

17. If you take a sphere and divide it into hemispheres, displacing each hemisphere relative to the other, and you do this enough times, “continents” will form

    1. only if there is a pattern to the hemispheric divisions

    2. even if there is no pattern to the hemispheric divisions

(b)

18. What is the source of 1/f noise?

    1. the lunar cycle

    2. the solar cycle

    3. solar radiation

    4. unknown

(d)

19. Mathematical skill beyond the freshman level in college is required to write programs to produce fractals.

    1. true

    2. false

(b)

20. How is the complexity of a fractal measured?

    1. by the dimension of the fractal

    2. by the length of its perimeter

    3. by the length of the escape orbit

    4. by the length of the shortest program needed to produce it

(d)

21. Which of the following is NOT a stable orbit?

    1. an orbit that moves toward the origin

    2. an orbit that moves toward infinity

    3. both (a) and (b)

    4. an orbit that stays on some perimeter

(d)

22. Inverse iteration used to compute orbits because it moves back toward the attractor rather than away from the attractor.

    1. true

    2. false

(b)

23. The actual Julia set is

    1. the perimeter

    2. the “filled in” region, excluding the perimeter

    3. the ”filled in” region, including the perimeter

(a)

24. To compute a “filled in” _______ set, z_k+1 = z_k² + c.

    1. Mandelbrot

    2. Julia

    3. Mandelbrot or Julia

(c)

25. “if it doesn’t move, it’s not animated.”

    1. true

    2. false

(b)

26. Which of the follows is second-to-lowest in the hierarchy (where “synopsis” is highest and “shot” is lowest)

    1. scenario

    2. scene

    3. sequence

    4. storyboard

(b)

27. Which typically comes first?

    1. the animation

    2. the sound track

(b)

28. When the camera is translated from one point to another, this is called a

    1. pan

    2. track

    3. tilt

(b)

29. A cross-dissolve is

    1. a fade-out followed by a fade-in

    2. synonymous with a wipe

(a)

30. Animation dates from

    1. the early 1600s

    2. the early 1800s

    3. the early 1900s

    4. the mid 1900s

(b)

31. For all intents and purposes, the use of animation is limited to entertainment (i.e. video games and cartoons for television and motion pictures).

    1. true

    2. false

(b)

32. Which is more advanced?

    1. key frame animation

    2. modeled animation

(b)

33. Morphing from a cube to a B-1 bomber involves techniques well beyond the scope of CS 455.

    1. true

    2. false

(b)